I was barely days into my English teaching job at a high school in Osaka when my pupils smashed the first of many stereotypes about the Japanese. Yes, their diligence and adherence to school dress codes confirmed all I had been told about the country's conscientious youth: they studied hard, they filled their free time with sports and cultural activities - and they slept.

It was not unusual, on a Monday morning, to ask young Taro to share with the rest of the class how he had spent his weekend, only to find him slumped over his desk, a little pool of dribble gathering on his unopened textbook.

I soon stopped treating classroom kipping as a challenge to my authority and allowed the serial sleepers to while away their 50-minute lessons in blissful ignorance. They were tired, Japanese colleagues told me, from baseball practice, cramming and part-time jobs. They were best left alone to dream.

Catching 40 winks is not only a classroom pursuit. At my next job, at a newspaper company, colleagues regularly took mid-afternoon catnaps at their desks. No one attempted to hide their habit. And no one, to my knowledge, was hauled before the editor for sleeping on the job.

If the harried souls on Tokyo's commuter trains are not text messaging, they are sleeping. The preference is for slouching over comic books or newspapers. Others jerk from side to side until they give up the fight and allow their head to rest on the shoulder of their neighbour. The seriously afflicted simply sleep where they stand, jolted out of their slumber only when their knees buckle.

Even so, almost a third of Japanese complain they do not get enough sleep, with many blaming their insomnia on long hours at the office and the stress of work.

Many do get their eight-hour daily quota, just not in the right place and at the right time. As a result, classrooms, offices and train carriages become makeshift sleeping quarters.

Though napping is widespread, allowing leaden eyelids to meet is considered a sign of personal weakness by the victims, if not by their teachers or bosses.

The shelves of high street chemists are packed with antidotes to drowsiness, from miniature bottles of potions enriched with caffeine and nicotine to chewing gum dotted with nuggets of strong mint to administer a figurative slap across the face.

But they now compete with an industry devoted to achieving the opposite: from specially designed pillows to CDs of soporific music, the aim is the same - to lead Japan's legions of delinquent sleepers to the land of nod.

My local branch of Tokyu Hands, a lifestyle store, has a large section devoted to sleep inducement. On sale are banana-shaped "hug pillows" for sleepers to wrap themselves around at night, eye masks filled with cooling gel, and no fewer than nine varieties of earplugs. There is even a cubicle fitted out with mattresses developed by Nasa that mould to the shape of your body as you drift off.

For those who blame tension for their sleepless nights, help comes in the form of electric and manual massagers. Many resemble instruments of torture, which - as anyone who has tried them knows - they are.

From next summer, insomniacs with a low pain threshold will be able to try Matsushita's Sleep Room, a computer-controlled combination of massage, soothing music, dim lighting and mould-to-body mattressing that can be theirs for just 30,000 dollars.

Cost aside, the science behind the remedies is questionable. My mother tried the cool gel eye mask on a flight home from Japan and said she was seeing double for hours after removing it. My own hug pillow was banished from my futon after a few uncomfortable nights.

Few would begrudge Japan's overworked, undervalued people a decent night's sleep, however they achieve it. But it will take new attitudes to work, not water-filled pillows and space technology, before that is possible.

In the meantime I make no apologies for nodding off on the train in the company of other committed snoozers. But sleeping on the job? I wouldn't dream of it.